Spray painting either by a robot or human operator generates a large amount of overspray waste. Overspray paint byproduct or paint waste generated in paint spraying operations takes the form of either a liquid sludge or semi-cured product embedded on a filter media. The term “overspray” means those coating components that miss the target substrate during spray application of the coating and in the absence of particular precautions are lost.
In the process of painting products, paint overspray and other chemicals are released into the atmosphere. If a paint booth is not properly maintained, it creates a health and safety hazard as well as an environmental hazard. There are two main methods for capturing these residual chemicals: dry filter scrubbers and water wash scrubbers.
The dry filter method involves capturing the overspray in filters by pulling the soil-laden air through the filter. As the filter captures the paints it also becomes chemically laden, and then must be disposed of properly. The major trend has been a movement toward dry filter booths; however, this ultimately creates more waste with the addition of the filters now being a waste product.
Water-wash paint booth systems capture oversprayed paint by using positive air pressure to force the particles into a cascading curtain of water. Various chemical and/or physical removal processes may be employed to remove the contaminants in the water. Theoretically, it is possible to recycle the water and the captured paint-by-product.
The water-wash design, because of its high efficiency and wet byproduct characteristics, has faced substantial challenges with the promulgation of more restrictive landfill regulations. It is becoming increasingly prohibitive, both economically and environmentally, to dispose of paint waste byproducts because of these regulations. Therefore, it is desirable to avoid the problem of disposal by recovering and recycling the overspray paint waste produced into a high quality paint product.
Paint is a tacky material and tends to coagulate and adhere to paint spray booth surfaces, particularly in sump and drain areas, and must constantly be removed from the sump to prevent clogging of the sump drain and recirculating system. In order to assist in the removal of the oversprayed paint from the air and to provide efficient operation of paint spray booths, detackifying agents are commonly employed in the water of such systems, and are typically incorporated into the water wash recirculated in the paint spray system. These agents may include, but are not limited to various fumed silicas. Detackifying the paint eliminates or minimizes the adhesive properties, or tackiness, of the paint, thereby preventing the oversprayed paint from adhering to the walls of the spray booth, etc.
The use of hydrophobic fumed silica (HFS) as a paint detackifier is known. This technology is efficient in detackifying overspray paint in some currently designed booths. For example, one approach to recovering paint overspray particles is described in U.S. Pat. No. 5,092,928 issued Mar. 3, 1992 to Spangler. This process includes bringing the paint particles into contact with a plurality of HFS by depositing a layer of HFS on the surface layer of the lower portion of the paint spray booth, then encapsulating and collecting the paint particles. This method has proven sufficient, however, due to the nature of the small, lightweight HFS particles, it is not a feasible material for many water wash booths. Additionally, there remains a need for a portable paint collection containment system, that may significantly reduce the amount of water required in the paint booth system, by re-using and reformulating the waste back into paint as well as reduce the
Therefore, a device is needed to employ and utilize detackification agents effectively in current and newly designed booths. A system where detackification of the process water is almost immediate and is cheaper than the conventional polymer detackification employed in current paint booth systems, and that re-uses and reformulates the waste back into paint as well as reduces the solvent emissions.